%04X 在 C 中的含义以及如何在 java 中编写相同的内容
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9902301/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Meaning of %04X in C and how to write the same in java
提问by Rog Matthews
In the java project i am working on, some portion of the project was written previously by someone else in C and now i need to write the same in Java.
在我正在处理的 java 项目中，该项目的某些部分以前是由其他人用 C 编写的，现在我需要用 Java 编写相同的内容。
There is a statement in C code for printing to a file:
C 代码中有一条语句用于打印到文件：
fprintf(ff, "%04X ", image[y*width+x]);
Firstly i am not sure about the meaning of %04X. I think it means that if image[i]has length five or more then print only leftmost four chararacters. To do the same in Java i thought about masking the value using andoperation
首先，我不确定%04X. 我认为这意味着如果image[i]长度为五个或更多，则只打印最左边的四个字符。为了在 Java 中做同样的事情，我想过使用and操作来屏蔽值
image[i] & 0xFFFF
Can someone please tell me the correct meaning of %04Xand how to do the same in Java? Thanks.
有人可以告诉我%04X在 Java 中的正确含义以及如何做同样的事情吗？谢谢。
回答by Andreas Dolk
The value is formatted as a hexadecimal integer with four digits and leading zeros. Java uses the same format string syntax. You can find it in the javaDoc of Formatter.
该值的格式为带有四位数字和前导零的十六进制整数。Java 使用相同的格式字符串语法。您可以在.java 文档中Formatter找到它。
Excerpt:
摘抄：
'x', 'X' integral The result is formatted as a hexadecimal integer
A related functions are
一个相关的函数是
// create a String with the formatted value.
String formatted = String.format("%04X ", image[y*width+x]);
// write a formatted value to the console (*)
System.out.printf("%04X ", image[y*width+x]);
(*) - write it to the PrintStreamSystem.outwhich is usuallythe console but can be redirected to a file or something else
（*） -它写入PrintStreamSystem.out这是通常的控制台，但可以重定向到文件或其他什么东西
回答by Some programmer dude
Lets break the format code "%04X"into its separate parts:
让我们将格式代码"%04X"分解为单独的部分：
- The
Xmeans that it will print an integer, in hexadecimal, largeXfor large hexadecimal letters - The
4means the number will be printed left justified with at least four digits, print spaces if there is less than four digits - The
0means that if there is less than four digits it will print leading zeroes.
- 这
X意味着它将打印一个整数，以十六进制表示，大X的十六进制字母 - 的
4数量将被打印装置左对齐，且至少四位数字，空格打印如果有不足4位 - 这
0意味着如果少于四位数，它将打印前导零。
回答by Thomas Padron-McCarthy
The X in %04X means hexadecimal, with ABCDEF instead of abcdef, and the 04 means print at leastfour digits, padding with leading zeros. It will use more digits if needed.
%04X 中的 X 表示十六进制，用 ABCDEF 代替 abcdef，04 表示打印至少四位数字，用前导零填充。如果需要，它将使用更多数字。
